JP3482450B2 - Electrophotographic photoreceptor and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having a high sensitivity in a wide wavelength range from visible light to near infrared light.

[0002]

2. Description of the Related Art In recent years, the development of information processing system machines using electrophotography has been remarkable. In particular, an optical printer that converts information into a digital signal and records information by light has excellent print quality and reliability. This digital recording technology is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. Further, since a copier in which this digital recording technology is mounted on a conventional analog copy is added with various information processing functions, its demand will be further increased in the future.

As a light source for an optical printer, a semiconductor laser (LD) and a light emitting diode (LED) which are small in size, inexpensive and highly reliable are currently widely used. The emission wavelength of the LED that is currently widely used is 660 nm,
The emission wavelength range of the LD is in the infrared light range. Therefore, development of an electrophotographic photosensitive member having high sensitivity in the visible light region to the near infrared light region is desired.

The photosensitive wavelength range of the electrophotographic photosensitive member is substantially determined by the photosensitive wavelength range of the charge generating substance used in the photosensitive member. Therefore, various charge generating substances such as various azo pigments, polycyclic quinone pigments, trigonal selenium and various phthalocyanine pigments have been conventionally developed. Of them,
A large number of pigments have been developed for azo pigments due to the ease of the pigment synthesis reaction and the variety of chemical structures. JP-A-64-
79753, JP-A-59-129857, Japanese Patent Publication No. 3
-34503, JP-B-4-52459, JP-A-62-62
The bisazo pigments having a diphenylpolyene skeleton described in JP-A-267363 and the trisazo pigments described in JP-A-57-195767 have a charging potential of sensitivity from the visible light region to the near infrared light region. Although it is a charge generating substance with high retention, the sensitivity is not yet sufficient to support future miniaturization and speeding up of information processing machines, and there has been a strong demand for a material for a further high-sensitivity photoconductor.

One of the inventors of the present invention has previously used at least 2θ = 6.8 ° from the powder X-ray diffraction pattern by Cu-Kα ray as the charge generating material in the laminated electrophotographic photosensitive member.
7.3 °, 2θ = 16 ° and 2θ = 24.5 ° to 26 °
It has been proposed to use an amorphous trisazo pigment having a specific structure having a diffraction peak in JP-A-61-151659. Certainly, by using the pigment, it is possible to obtain a laminated type electrophotographic photoreceptor having high sensitivity in the visible region to the near-infrared region and excellent in repeated fatigue characteristics, but it can be used for speeding up the copying process of copying machines, printers, etc. Along with this, it has been desired to further increase the sensitivity of the photoconductor.

[0006]

SUMMARY OF THE INVENTION In view of such circumstances of the prior art, the present invention provides an electrophotographic photosensitive member having a high sensitivity over a wide wavelength range from the visible light region to the near infrared light region in the whole range of the invention, and It is intended to provide a manufacturing method thereof.

[0007]

Means for Solving the Problems The present inventors have proposed the above structural formula [I] for absorbing light in the wavelength range from visible light to near infrared light.
As a result of research on increasing the sensitivity of an electrophotographic photosensitive member using the trisazo pigment, the trisazo pigment was found to be Cu-K.
The X-ray diffraction spectrum for α-ray has a diffraction peak at a Bragg angle of 7 ± 0.3 °, and the half width of the peak at the Bragg angle of 7 ± 0.3 ° is 1.2 ° to
It was found that a high-sensitivity electrophotographic photoreceptor can be obtained when it shows a diffraction spectrum of 1.6 °, and the present invention was completed. Further, the present inventors have found that the trisazo pigment of the structural formula [I] having such an X-ray diffraction pattern has a temperature of 30 ° C.
As described above, the present invention has been completed by discovering that it can be produced by applying and drying the dispersion produced by heating and dispersing. Further, the present inventors have prepared a dispersion liquid prepared by mixing and dispersing the trisazo pigment of the structural formula [I] having the X-ray diffraction pattern with the trisazo pigment and an organic pigment other than the trisazo pigment. The present invention was completed by discovering that it can be produced by applying and drying.

The mechanism of increasing the sensitivity of the azo pigment exhibiting such a specific X-ray diffraction pattern has not been clarified at present, but it can be inferred as follows. According to the study by the present inventors, the photocarrier generation of the function-separated electrophotographic photoreceptor using one of the trisazo pigments represented by the structural formula [I] of the present invention is caused by the trisazo pigment and the charge transport material. It has been found that it is caused between (Journal of Applied Physics, Vol. 72, pages 117-123). On the other hand, such photo-carrier generation at the charge generation material / charge transport material interface is
It was found that it was governed by the amount of contact between the two at the interface (Journal of Imaging Science and Technology, Vol. 38, 281-286).
page). In addition, it was revealed that the carrier generation between the azo compound and the charge transport material is extremely low in the state where the azo compound is monomolecularly dispersed (Advance Materials, Vol. 7, 481). ~ 483).
Based on the above findings, it is considered that the azo pigment has the most suitable particle size for generating photocarriers.

Now, as is clear from the embodiment described later,
The half width of 7 ± 0.3 ° of the azo pigment is 1.2 ° to 1.6.
It was found that the highest sensitivity was obtained in the case of °, and the sensitivity became lower when the half width was larger or smaller than that. It is considered that such a phenomenon that the half width of the X-ray diffraction peak becomes large is because the pigment is changed to an amorphous state or the crystal becomes finer. However, the existence of the full width at half maximum of the X-ray diffraction peak in the optimum range of the present invention described above is
It is considered as follows. It is considered that in the region where the sensitivity becomes higher as the half-value width becomes larger, the surface area of the trisazo pigment becomes larger so that the contact amount with the charge transport material increases and the carrier generation amount increases. On the contrary, it is considered that in the region where the sensitivity does not increase even if the half-width becomes large, the azo pigment particles become finer or become amorphous and thus come closer to a monomolecular state, which is against the generation of carriers.

According to the present invention, when an azo pigment exhibiting such a specific X-ray diffraction pattern is used as a charge generating material in an organic photoreceptor, a laminated photoreceptor comprising a charge generating layer and a charge transport layer is particularly preferable. It was found to exhibit high sensitivity.

Further, as a result of intensive studies by the present inventors, in the X-ray diffraction spectrum for the Cu-Kα line of the structural formula [I] considered to have such an optimum particle size, at least the Bragg angle of 7 ±. A method for obtaining a trisazo pigment dispersion liquid having a diffraction peak at 0.3 °, and further showing a diffraction spectrum of the peak at the Bragg angle of 7 ± 0.3 ° of 1.2 ° to 1.6 ° was found. The present invention has been completed.

According to the present invention, the following inventions are provided. (1) In a dispersion solvent, a trisazo pigment represented by the following structural formula [I] having an X-ray diffraction spectrum for Cu-Kα line having a diffraction peak at a Bragg angle of 7 ± 0.3 ° on a conductive support is dispersed. The dispersion obtained by heating and dispersing in the range of 30 ° C. or higher and 56 ° C. is a dispersion in which the half width of the peak at Bragg angle 7 ± 0.3 ° is 1.2 ° to 1.6 °.
A method for producing an electrophotographic photosensitive member, which comprises the steps of coating and drying.

[Chemical 1] (In the formula, R ¹ and R ² represent an alkyl group, an alkoxy group, a halogen atom, a dialkylamino group, a halomethyl group, a nitro group, a cyano group, a carboxyl group or an ester thereof, a hydroxyl group or a sulfonate, and m is 0 to An integer between 5 and n represents an integer between 0 and 4.) (2) A trisazo pigment represented by the structural formula [I] and an organic pigment other than the trisazo pigment are mixed on a conductive support. Then, the trisazo pigment represented by the structural formula [I] has a Bragg angle of 7 ± 0.3 ° of a peak in the dispersion obtained by heating and dispersing the dispersion solvent in the range of 30 ° C. to 56 ° C. Apply the dispersion with a half-value width of 1.2 ° to 1.6 °
The method for producing an electrophotographic photosensitive member according to (1), which includes a step of drying. (3) In the method for producing an electrophotographic photosensitive member comprising a charge generation layer and a charge transport layer laminated on a conductive support, the charge generation layer is represented by the structural formula [I], The trisazo pigment represented by the structural formula [I] has a Bragg angle of 7 ± 0.3 ° with a half-value width of 1 in a dispersion obtained by heating and dispersing in a solvent in the range of 30 ° C. to 56 ° C. It is characterized in that it is produced by a step of applying and drying a dispersion liquid of 2 ° to 1.6 ° (1) or (2).
A method for producing the electrophotographic photosensitive member described.

The X-ray diffraction spectrum referred to in the present invention is for measuring a powdery charge generating material by a powder method. If copper is used as the anticathode of the X-ray tube and nickel is used as the filter, Cu-Kα rays (1.5418Å) can be extracted. According to the studies by the present inventors, the above structural formula [I]
Cu-Kα by a powder X-ray diffraction method (using PW1729 / 00 manufactured by Philips) with the trisazo pigment represented by
When measured with a line at a tube current of 40 kV and a scanning speed of 1 ° per minute, there is a diffraction peak at least 2θ = 7 ± 0.3 °, and the full width at half maximum of the peak is 1.2 ° to 1.6 °. It has been revealed that an electrophotographic photoreceptor having a very high sensitivity can be obtained in the range. The full width at half maximum of the peak at the Bragg angle of 7 ± 0.3 ° in the measured X-ray diffraction spectrum connects the rising points a and b from the baseline level including noise as shown in FIGS. 1 and 2. It is defined by the value of the angle indicated by the length of the line segment ef that passes through the midpoint of the line segment cd starting from the intersection point d of the line segment and the perpendicular line drawn from the vertex c and is parallel to the X axis (diffraction angle). Shall be.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the drawings. FIG. 3 is a cross-sectional view showing an electrophotographic photosensitive member used in the present invention, in which a single-layer photosensitive layer 33 containing a charge generating material and a charge transporting material as main components is provided on a conductive support 31. . FIG. 4 and FIG. 5 are cross-sectional views showing another configuration example of the electrophotographic photosensitive member used in the present invention. The charge generating layer 35 containing a charge generating material as a main component and the charge transporting material as a main component. The charge transport layer 37 and the charge transport layer 37 are laminated.

The conductive support 31 has a volume resistance of 10
Films with a conductivity of ¹⁰ Ωcm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold and platinum, and metal oxides such as tin oxide and indium oxide, formed by vapor deposition or sputtering. Alternatively, use cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stellenless plates, etc. and pipes that have been surface-treated by cutting, superfinishing, polishing, etc. You can

Next, the photosensitive layer will be described. The photosensitive layer may be a single layer or a laminated layer, but for convenience of description, the case where it is composed of the charge generation layer 35 and the charge transport layer 37 will be described first. The charge generation layer 35 is made of Cu-Kα as a charge generation material.
X-ray diffraction spectrum for the X-ray has a diffraction peak at least at a Bragg angle of 7 ± 0.3 °, and the half width of the peak at the Bragg angle of 7 ± 0.3 ° is 1.2 ° to 1.
It is a layer containing 6 ° of a trisazo pigment represented by the following structural formula [I] as a main component.

[0017]

[Chemical 1] (In the formula, R ¹ and R ² are an alkyl group, an alkoxy group, a halogen atom, a dialkylamino group, a halomethyl group, a nitro group, a cyano group, a carboxyl group or an ester thereof,
It shows a hydroxyl group or a sulfonate, m is an integer between 0 and 5, and n is an integer between 0 and 4. )

The trisazo pigment represented by the above structural formula [I] has triphenylamine as an azo component and is chemically bonded to a coupler component through an azo group.
As the coupler residue of the trisazo pigment used in the present invention, those shown in Tables 1 to 4 are exemplified as typical examples and are useful.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

It is possible to use a charge generating material other than the trisazo pigment in combination with the trisazo pigment represented by the structural formula [I]. Typical examples thereof are monoazo pigments, disazo pigments, trisazo pigments and perylene. Pigments,
Perinone-based pigments, quinacridone-based pigments, quinone-based condensed polycyclic compounds, squalic acid-based dyes, phthalocyanine-based pigments, naphthalocyanine-based pigments, azurenium salt-based dyes and the like can be used.

A binder resin may be used in combination with the charge generation layer 35 of the present invention. As the binder resin, polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polyacrylamide or the like is used.

The charge generation layer 35 has at least a Bragg angle of 7 ± in the X-ray diffraction spectrum for Cu-Kα rays.
It has a diffraction peak at 0.3 ° and the Bragg angle is 7 ±
Tetrahydrofuran, cyclohexanone, dioxane, which contains the trisazo pigment represented by the structural formula [I] having a half-value width of a peak at 0.3 ° of 1.2 ° to 1.6 °, optionally containing other charge generating material and a binder resin, 2-butanone,
It can be formed by applying a dispersion liquid using a suitable solvent such as dichloroethane. To prepare the charge generation layer containing the structural formula [I] showing the X-ray diffraction pattern,
It can be prepared by coating and drying a dispersion liquid produced by heating and dispersing a trisazo pigment at 30 ° C. or more, and mixing and dispersing a trisazo pigment and an organic pigment other than the trisazo pigment. It can be produced by applying and drying the dispersion liquid produced by.

As a dispersing means for obtaining the dispersion, known methods such as a ball mill, an attritor, a sand mill, a vibration mill, a disk vibration mill, a paint shaker and a jet mill can be mentioned and used. However, the target X
Since the dispersion conditions for obtaining the line diffraction pattern differ depending on the dispersion conditions, they cannot be uniformly defined. It can be considered that the reason is that the ratios of the crushing power, the dispersing power, the polishing power, etc. are different depending on the dispersing means or the use conditions thereof.

In the X-ray diffraction spectrum for Cu-Kα rays, there is a diffraction peak at least at Bragg angle of 7 ± 0.3 °, and the half width of the peak at Bragg angle of 7 ± 0.3 ° is 1.2 °. One of the methods for producing a dispersion liquid containing the trisazo pigment represented by the structural formula [I] of about 1.6 ° is a method of performing dispersion while heating. The dispersion temperature at the time of dispersion is 30 ° C. As described above, when the dispersion is carried out while heating at preferably 35 ° C. or higher, the desired dispersion liquid is obtained. As another method for obtaining the intended dispersion liquid, a means for dispersing the trisazo pigment of the structural formula [I] together with the charge generating material other than the trisazo pigment at the same time without mixing, is preferably used. In this case, heating at the time of dispersion may or may not be performed. However,
As described above, the method described here is a means for efficiently obtaining the target dispersion liquid, but it does not mean that the target dispersion liquid can be reliably obtained even by following these methods. Should be inscribed.

When the other charge generating material is mixed with the trisazo pigment of the structural formula [I], the ratio of the two is preferably 0 to 10 parts by weight, more preferably 1 part by weight of the trisazo pigment. It is 0 to 20 parts by weight. In the charge generation layer 35, the ratio of the resin to 1 part by weight of the charge generation material is 1.5 parts by weight or less, preferably 0 to 1 part by weight, and the film thickness is suitably about 0.01 to 5 μm, and preferably It is 0.1 to 2 μm.

The charge transport layer 37 is prepared by dissolving or dispersing a charge transport material and an appropriate binder resin in an appropriate solvent,
It can be formed by applying and drying this. Further, if necessary, a plasticizer, a leveling agent, etc. can be added. The charge transport layer 37 is composed of a charge transport material and a binder resin.

The charge transport material includes a hole transport material and an electron transport material. Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, 3,5-dimethyl-3 ',
Known electron-accepting substances such as 5'-ditertiarybutyl-4,4'-diphenoquinone can be mentioned. Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls. Other known materials such as a methane derivative, a 9-styrylanthracene derivative, a pyrazoline derivative, a divinylbenzene derivative, a hydrazone derivative, an indene derivative and a butadiene derivative can be mentioned and used. These charge transport materials may be used alone or in combination of two or more.

As the binder resin, polystyrene,
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, Thermoplastic or thermosetting resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin can be used.

As the solvent, tetrahydrofuran, dioxane, toluene, 2-butanone, monochlorobenzene, dichloroethane, methylene chloride or the like can be used.
In the charge transport layer 37, the ratio of the charge transport material to 1 part by weight of the binder resin is 0.3 to 2 parts by weight, preferably 0.5 to 1.4 parts by weight, and the film thickness is 5 to 100.
μm is suitable.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 37. As a plasticizer,
Those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used.

Next, the case where the photosensitive layer has a single-layer structure 33 will be described. Also in this case, a function-separated type material including a charge generation material and a charge transport material is used. That is, the charge-generating material and the charge-transporting material can be formed by dissolving or dispersing them in a suitable solvent together with a binder resin, if necessary, and coating and drying them. As the charge generating material and the charge transporting material, those described above can be used, and as the binder resin, the resins used for the charge transporting layer mentioned above can be used as they are, and if necessary, they can be used for the charge generating layer. A resin that can be used may be used in combination. Also,
If necessary, a plasticizer, a leveling agent, etc. can be added.

In the single-layer photosensitive layer, the ratio of the charge generating material to 1 part by weight of the binder resin is 0.01 to 100 parts by weight, preferably 0.02 to 50 parts by weight, and the charge transporting amount to 1 part by weight of the binder resin. The proportion of material is 0.3 to 2 parts by weight, preferably 0.5 to 1.4 parts by weight. The film thickness is preferably 5 to 50 μm.

In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support 31 and the photosensitive layer. A known material can be used for the undercoat layer. The thickness of the undercoat layer is suitably 0 to 5 μm.

In the electrophotographic photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. A known material is provided for the protective layer by a known method.
A suitable thickness of the protective layer is about 0.5 to 10 μm.

[0038]

EXAMPLES Examples will be shown below, but the examples explain the present invention in detail, and the present invention is not limited to the examples. All parts in the examples are parts by weight.

Example 1 3 parts of the compound of the structural formula [I] shown by the following structure, 1 part of butyral resin and 200 parts of cyclohexanone were put in a ball mill and dispersed at 30 ± 0.5 ° C. to obtain a dispersion liquid. This dispersion was applied onto a polyester film having an aluminum conductive layer and dried to provide a charge generation layer so that the dry film thickness would be 0.2 μm.

[Chemical 2]

A charge-transporting layer coating solution having the following composition was applied thereon and dried to provide a charge-transporting layer having a dry film thickness of 25 μm, to produce the electrophotographic photoreceptor of the present invention. <Charge transport layer coating liquid> 10 parts of charge transport material having the following structure

[Chemical 3] Polycarbonate (Iupilon Z-300, manufactured by Mitsubishi Gas Chemical Company) 13 parts Methylene chloride 90 parts

The dispersion liquid of the trisazo pigment represented by the structural formula [I] was coagulated and dried, and the powder X-ray diffraction measurement was performed. As a result, the X-ray diffraction spectrum shown in FIG. 6 was obtained.
From FIG. 6, the trisazo pigment has at least a Bragg angle of 7 ±.
It has a diffraction peak at 0.3 ° and a half-value width of the peak of 1.2.
It can be seen that it is 7 °.

Examples 2 to 6 and Comparative Examples 1 to 4 Examples 2 to 6 and Comparative Examples were carried out in the same manner as in Example 1 except that the dispersion temperature of the ball mill was changed to the temperature shown in Table 5. Photoconductors 1 to 4 were obtained.

Comparative Example 5 In producing a dispersion containing the compound of the structural formula [I] produced in Example 1, a vibration mill was used instead of a ball mill, and dispersion was performed at room temperature (25 to 30 ° C.). A photoreceptor of Comparative Example 5 was manufactured in the same manner as in Example 1 except that the above was used.

Comparative Example 6 In dispersing the compound of the above structural formula [I] used in Example 1, first, only the trisazo pigment was dry-milled in a ball mill, and then a resin and a solvent were added to carry out wet dispersion to disperse. Comparative Example 6 was manufactured in the same manner as in Example 1 except that the liquid was manufactured (temperature between 23 and 27 ° C during this time).

Each of the photoconductors manufactured as described above was applied to an electrostatic copying paper test apparatus [EPA-manufactured by Kawaguchi Electric Co., Ltd.].
8100] was used to perform the following measurement. First,
After charging by -6 kV corona discharge for 15 seconds,
The surface potential of the photoreceptor is -10 by irradiating the tungsten lamp light with monochromatic light having an illuminance of 1 μW / cm ² through a monochromatic light filter through dark decay until the surface potential of the photoreceptor becomes −800V.
The time to decay to 0V, Δt, is measured, and the sensitivity S
Converted to. S = (800-100) / (1 × Δt) [Vcm ² / μ
J] Table 5 shows the measurement results of each photoconductor. The powder X-ray diffraction patterns of Examples 2 to 6 and Comparative Examples 1 to 6 were all the same as that of Example 1, but the full width at half maximum of the diffraction peak at the Bragg angle of 7 ± 0.3 ° was as shown in Table 5. Changed to.

[0046]

[Table 5]

Example 7 The following trisazo pigment was used in place of the trisazo pigment of the structural formula [I] in Example 2, and the charge transporting material used in the charge transporting layer was changed to the one having the following structural formula. In the same manner as in Example 2, a photoconductor of Example 7 was manufactured. <Charge generating material>

[Chemical 4]

<Charge Transport Material>

[Chemical 5]

Comparative Example 7 A photoconductor of Comparative Example 7 was manufactured in the same manner as in Example 7, except that the dispersion temperature was changed to 20 ± 0.5 ° C. in Example 7.

Example 8 The following trisazo pigment was used instead of the trisazo pigment of the structural formula [I] in Example 3, and the charge transporting material used in the charge transporting layer was changed to that of the following structural formulae. In the same manner as in Example 3, a photoconductor of Example 8 was manufactured. <Charge generating material>

[Chemical 6]

<Charge Transport Material>

[Chemical 7]

Comparative Example 8 A photoconductor of Comparative Example 8 was manufactured in the same manner as in Example 8 except that the dispersion temperature in Example 8 was changed to 25 ± 0.5 ° C.

Comparative Example 9 In producing a dispersion containing the compound of the above structural formula [I] produced in Example 8, all operations were carried out except that an attritor was used instead of a ball mill and dispersion was carried out at 25 ° C. A photoreceptor of Comparative Example 9 was manufactured in the same manner as in Example 8.

Comparative Example 10 Comparative Example 1 was carried out in the same manner as in Example 1 except that the trisazo pigment dispersion solvent was changed to toluene.
0 photoreceptors were produced. The powder X-ray diffraction spectrum of the trisazo pigment at this time is shown in FIG. 7, but there is no diffraction peak at 7 ± 0.3 °.

Comparative Example 11 A photoconductor of Comparative Example 11 was manufactured in the same manner as in Example 2 except that the solvent for dispersing the trisazo pigment in Example 2 was changed to tetrahydrofuran. The powder X-ray diffraction spectrum of the trisazo pigment at this time is shown in FIG.
There is no diffraction peak at 0.3 °.

The powder X-ray diffraction patterns of Examples 7 and 8 and Comparative Examples 7 to 9 were all the same as in Example 1, but the full width at half maximum of the diffraction peak at Bragg angle 7 ± 0.3 ° is shown in Table 6. It changed as shown in.

[0057]

[Table 6]

[0058]

[0059]

[0060]

[0061]

Examples 13 and 14 On an aluminum plate having a thickness of 0.2 mm, an undercoating having the following composition was applied.
Layer coating liquid is applied and dried to give a dry film thickness of 2.5 μm
Layers were formed. <Undercoat layer coating liquid> Titanium dioxide powder 30 parts (Ishihara Sangyo Co., Ltd .: Taipaque R-670) Alkyd resin 5 parts (Dainippon Chemical Industry Co., Ltd .: Beckozol 1307-60-EL) Melamine resin 5 parts (Dainippon chemical industry Co., Ltd. SUPER BECKAMINE G-821-60) 4-compound 2 parts of methyl-2-pentanone 50 parts the structural formula represented by the following structural [I] and X
Type Metal-free phthalocyanine 1 part and butyral resin 2 parts and 2
-Put 200 parts of butanone in a ball mill and disperse at room temperature.
A dispersion was obtained. This dispersion is on the undercoat layer prepared above
Apply and dry it on the electrode to make the dry film thickness 0.3 μm.
A load generation layer was provided.

[Chemical 2] On top of that, apply and dry a charge transport layer coating liquid having the following composition,
A charge transport layer having a dry film thickness of 30 μm is provided, and the electron transfer of the present invention is performed.
A true photoreceptor was produced. <Coating liquid for charge transport layer> 8 parts of charge transport material having the following structure

[Chemical 8]     Polycarbonate (Panlite K-1300, Teijin Chemicals) 11 parts     90 parts of methylene chloride Instead of the X-type metal-free phthalocyanine, shown in Table 7
Using charge generation material . Disperse the charge generation layer coating liquid to 35
Example 13 was carried out in exactly the same manner except that it was carried out at ± 0.5 ° C.
And the photoconductor of Example 14 were manufactured.

The sensitivity S of each of the photoconductors manufactured as described above was measured. Table 8 shows the measurement results of each photoconductor. The powder X-ray diffraction patterns of Examples 9 to 14 were all the same as that of Example 1, but the half-width of the diffraction peak at the Bragg angle ± 0.3 ° was changed as shown in Table 8.

[0064]

[Table 7]

[0065]

[Table 8]

Example 15 2 parts of polyester (Vylon 200, manufactured by Toyobo Co., Ltd.) was added to 100 parts of the trisazo pigment dispersion liquid prepared in Example 3.
0 parts, 15 parts of a charge transport material having the following structural formula, and 90 parts of tetrahydrofuran were added and dissolved. Apply this coating solution on an aluminum plate with a thickness of 0.2 mm and dry it to obtain a dry film thickness of 2
A 0 μm single-layer photosensitive layer was formed.

[Chemical 9]

Comparative Example 12 Comparative Example 12 was carried out in the same manner as in Example 15 except that the trisazo pigment dispersion liquid prepared in Comparative Example 4 was used in place of the dispersion liquid prepared in Example 3. A single layer photoreceptor was produced.

[0068]

[0069]

[0070]

[Table 9]

[0071]

According to the present invention, by using the trisazo pigment specified by the specific X-ray diffraction pattern and the half-value width of the diffraction peak as the charge generating material of the electrophotographic photoreceptor, the near red region from the visible light region can be obtained. It is possible to obtain an electrophotographic photosensitive member having high sensitivity over a wide wavelength range up to the outside light range. Further, according to the method for producing an electrophotographic photosensitive member of the present invention, a trisazo pigment specified by a specific X-ray diffraction pattern and a half-value width of a diffraction peak can be provided as a charge generating material of the electrophotographic photosensitive member, and thus visible It is possible to stably obtain an electrophotographic photosensitive member having high sensitivity over a wide wavelength range from the light range to the near infrared light range.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a half width of a peak of an X-ray diffraction spectrum.

FIG. 2 is a diagram for explaining a half width of a peak of an X-ray diffraction spectrum.

FIG. 3 is a schematic cross-sectional view showing the layer structure of an electrophotographic photosensitive member (single-layer type) of the present invention.

FIG. 4 is a schematic cross-sectional view showing the layer structure of an electrophotographic photosensitive member (multilayer type) of the present invention.

FIG. 5 is a schematic cross-sectional view showing another layer structure of the electrophotographic photosensitive member (multilayer type) of the present invention.

FIG. 6 is an X-ray diffraction spectrum of a trisazo pigment obtained by coagulating and drying the dispersion liquid of Example 1.

7 is an X-ray diffraction spectrum of a trisazo pigment obtained by coagulating and drying the dispersion liquid of Comparative Example 10. FIG.

FIG. 8 is an X-ray diffraction spectrum of a trisazo pigment obtained by coagulating and drying the dispersion liquid of Comparative Example 11.

[Explanation of symbols]

31 conductive support 33 Single-layer photosensitive layer 35 Charge generation layer 37 Charge Transport Layer

─────────────────────────────────────────────────── --- Continuation of front page (56) References JP-A-61-151659 (JP, A) JP-A-7-239561 (JP, A) JP-A-7-168380 (JP, A) JP-A-7- 84389 (JP, A) JP-A-7-13372 (JP, A) JP-A-6-236054 (JP, A) JP-A-5-341546 (JP, A) JP-A-2-226257 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 5/00

Claims (3)

(57) [Claims] 1. An X-ray diffraction spectrum for Cu-Kα rays on a conductive support having a Bragg angle of at least 7 ± 0.3.
The trisazo pigment represented by the following structural formula [I] having a diffraction peak at a temperature of 30 ° C. or higher and 56 ° C.
The dispersion obtained by heating the dispersion at a circumference at Bragg angles 7 ±
A method for producing an electrophotographic photosensitive member, comprising a step of coating and drying a dispersion liquid having a half-value width of a peak at 0.3 ° of 1.2 ° to 1.6 °. [Chemical 1] (In the formula, R ¹ and R ² represent an alkyl group, an alkoxy group, a halogen atom, a dialkylamino group, a halomethyl group, a nitro group, a cyano group, a carboxyl group or an ester thereof, a hydroxyl group or a sulfonate, and m is 0 to An integer between 5 and n represents an integer between 0 and 4.) 2. A trisazo pigment represented by the structural formula [I] and an organic pigment other than the trisazo pigment are mixed on a conductive support, and the mixture is mixed in a dispersion solvent at a temperature of 30 ° C. to 56 ° C.
Of the trisazo pigment represented by the structural formula [I] in a dispersion liquid obtained by heating and dispersing in a temperature range of 7 ± 0.
The method for producing an electrophotographic photosensitive member according to claim 1, further comprising a step of applying and drying a dispersion liquid having a half-value width of a 3 ° peak of 1.2 ° to 1.6 °. 3. A method of manufacturing an electrophotographic photosensitive member comprising a charge generating layer and a charge transporting layer laminated on a conductive support, wherein the charge generating layer is represented by the structural formula [I]. The half value width of the peak of the Bragg angle of 7 ± 0.3 ° of the trisazo pigment represented by the structural formula [I] in the dispersion obtained by heating and dispersing in a dispersion solvent in the range of 30 ° C. to 56 ° C. It is produced by a step of applying and drying a dispersion liquid having an angle of 1.2 ° to 1.6 °.
Or the method for producing the electrophotographic photosensitive member according to 2.